Starting early next year, the venerable NY Times is going to include ebooks in its weekly literary sales ratings. Taking their place alongside paperbacks and hardcovers, ebooks will be ranked based on a system that it took the Grey Lady two years to perfect:

"We've had our eye on e-book sales since e-books began," Ms. Elder said. "It was clear that e-books were taking a greater and greater share of total sales, and we wanted to be able to tell our readers which titles were selling and how they fit together with print sales."

While it'll be nice for publishers to puff about how their ebooks are selling, it's also an important validation for the Kindles and Nooks and iBooks of the world.

I'm curious, too, to see how the rankings ultimately pan out. Will it be based on volume, price, a mixture? What weight will be given to different platforms?